Process of manufacturing insulator pins



Feb. 12,, 1929.

A. o. AUSTIN -PROCESS OF MANUFACTURING INSULATOR PINS Filed March 1.192's 2 Sheets-Sheet 1 INVENTOR By M 8% 1 A TITORNE rs Feb. 12, 1929.

. A. O. AUSTIN PROCESS OF MANUFACTURING YINSULA'I'OR PINS Filed March 1,1923 2 Sheets-Sheet 2 fl/NVENTOR BY 7 A TTORNE V ARTHUR O. AUSTIN, OFBARBERTON, OHIO, ASSIGNOR, BY MESFTE ASSI(3N111715151"!S, TO

. viewpoint.

Patented Feb. 12, 1929.

UNITED STATES PATENT. OFF'ICE.- V

THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEY.

rnoon'ss' or MANUFACTURING INsULA'roR rms.

Application filed March I, 1923. Serial No. 621,966. I

This .invention relates to supports for electrical insulators having apin on which the insulator is mounted and means for securing the p n toa cross arm or ber'. 'Ihe invention has for its object the provislon ofan economical and simple method of manufacturing insulator pins whichmaybe easily assembled in place on their supports and which are efficient'in operation both from a mechanical and an electrical The inventionalso contemplates simplification and lmprovement of the pin itself so,

' as to facilitate the process of manufacture mem and provide a pin ofmaximum eifi'ciency. The invention is exemplified in the combinat10n andarrangement of parts shown in the accompanying drawings and described inthe following specification and it is more particularly pointed out inthe appended claims.

In the drawings Fig. 1 is an elevation of one form of insulator pinmanufactured according to the present invention.

Fig. 2 shows a base member.

slightly modified form pf Fig. 3 illustratesone step ofthe processofmanufacturing the base member.

Fig. 4 illustrates another step in the process.

Figs. 5 and 6 illustrate two steps of the process as performed withslightly different tools from those illustrated in Figs. 3 and 4.

Fig. 7 shows another form of tool that may be used.

' Fig. 8 is a punching and before the final finishing operation.

Fig. 9 is a top plan view of another form of base member.

Fig. 10 is a vertical section of the base member shown in Fig.- 9 andillustrates the finishing operation therefor.

Fig. 11 is a section on line 1111 of Fig. 10. Fi 12 is a top plan ofanother form of base Fig. 13 is a vertical section of the member shownin Fig. 12 and illustrates the finishing operation therefor.

As shown in Fig. 1', the numeral 10 designates the body portion of aninsulator pin which may be forged or otherwise formed of iron or steeland is preferably galvanized,

other supporting mem "greatest section of the base member after i drawntightly to teriaL A thimble of lead for other similar materlal is formedon the upper end of the p1n forthe purpose of providing a suitableconnection with the insulator.

In order to support the pin upon the cross arm it is desirable to have abase member 12 having a considerable bearing surface 13 to rest upon theupper face ofthe support. It 1s mpractical from a manufacturingstandpoint to'form this supporting flange integrally with the main bodyof the pin 10 for thereason that such a method of manufacture wouldeither require very great amount of metal to reduce the other parts totheir proper size or else the expansion by upsetting or other processesof the cutting away of a Y the portion of the metal to form the flange.Both of these methods of manufacture are diflicult and expensive. Wherea separate base is provided it is desirable that the strength of the pinshall not be reduced at thepoint where it enters the support, for thisis the portion of the pin subjected to the bending moments. It is alsodesirable that the parts may be readily assembled and easily attached tothe support and that a firm connection shall be established between thepin and base member so that they will act substantially as one pieceboth as to rotary and laterally acting forces. It has been found that aplain taper 14 in the base member 12 which fits a corresponding taper,

on the pin is well adapted to secure these results. This permits thebase member to reinforce the portion of the pin where it is reduced topass thru the cross arm and also insures a tight fit between the baseand pin, since the pin is drawn tightly into the taper by the nut 15threaded to the pin beneath the cross arni. The perforation thru thebase 12 is preferably provided with a straight por-' tion 16 at thebottom thereof to insure proper bearing of the tapered surfaces on thepm and base. When the two fitting tapers are gether the friction betweenthe surfaces will resist relative rotation of the pin and base and willcause the two to act substantially as one piece. Where it is desired tohold the pin against rotation on the cross arm while screwing theinsulator on the pin the base may be provided with teeth or projections17 as shown in Fig. 2 of the drawing. In that figure the supportmg baseis curved as shown at 18 to fit the upper curved surface of the roundedcross arm. It will be understood that the teeth 17 may be formed on afiat base such as that shown in Fig. 1 as well as upona curvedsupporting surface illustrated in Fig. 2.

In manufacturingthe base member 12, ithas been found impractical toaccurately form the perforation for receiving the pin by the ordinaryforging process for the reason that it is difficult to maintain theforging tools sufliciently accurate to provide an accurate fit for thepin and base. Forging deep recesses is also a diflicult operation. Toovercome these difficulties, according to the present invention the basemember 12 is first forged into a shape similar to that illustrated inFigs. 3 and 5 in which the central perforation is formed part way thruthe base from both of the opposite sides. This avoids the necessity offorming excessively deep recesses by the forging process and at the sametime makes perforation sufiiciently deep that the remaining metal 17 maybe severed from the base member by drilling or punching to complete theperforation. In finishing the base from the forging as shown in Fig. 5the metal 17 may first be drilled from the center of the forging and thetapered open-' ing may then be completed by means of a reamer of propersize and taper. Another method of completing the base is to insert acylindrical punch into the upper tapered opening as illustrated in Fig.5v and force the material 17 downwardly completing the perforation, theforging being held by a suitable supporting die 18 (Fig. 3) having astripper 19 connected therewith. After the punching operation a tapereddrift tool 20, Fig. 7, is forced into the tapered opening, the drifttool 20 being of proper size and taper to correspond to the taperedportion of the pin 10. The finishing operations may be performed withthe metal either hot or cold. A single tool may be employed asillustrated in Figs. 3 and 4 for both punching and shaping the interiorof the perforation, but if separate tools are used it is found that insome cases less difficulty will be experienced in maintaining the toolsin proper condition. The drift tool may in some cases be pro vided witha guiding boss or pilot 21, as shown in Fig. 7, or this guide may beomitted as shown in Fig. 6. After punching, the base member will havethe form illustrated in Fig. 8 and the metal inside the broken lines 22will be forced back by the finishing tool to give the correct tapershown by these lines.

In Figs. 9, 10 and 11 there is shown a base member having a taperedsocket with angular sectional shape. This can be finished from the formof forging shown in Figs. 3 and 5 by a punch like that shown at 22',Fig. 10.' The base may be provided with ears 23 to hold it from turningon the base while an insulator is screwed to the top of the pin,

Which will of course be provided with an angulartaper portion to fit thesocket 1n the base member. The base member is also pro 'vided with anouter angular portion 27, upon 24 through which bolts or cap screws maybe passed for securing it to its support. In this form the underside ofthe base is recessed at 25 to receive a nut 26 for holding the pin to athe base. This form is especially. valuable for use with bus bars andother installations where the base is anchored on the support.

I claim: i

1. The process of manufacturing an insulator pin wherein a pin body andbase are separately formed the base being shaped and partiallyperforated by forging after which the perforation is completed by asevering operation the interior of said perforation being given apredetermined taper to correspond to a tapered portion of said pin bodythe shape of said tapered perforation being produced by a tool ofcorresponding shape and size which is forced into said perforatheinterior thereof is given a tapered formation to fit a tapered portionof a pin to be supported thereby said tapered formation being impartedto said perforation by a drift tool forced into said perforation.

3. The process of manufacturing an insulator support wherein a pin bodyand a base member are separately formed said base member being roughlyformed by forging and being finished to provide a perforation therethru,having a tapered portion of predetermined size and shape to correspondto a similar tapered portion on said pin body, the pin body beinginserted in said base member and secured in place in said base member byan attaching means arranged to draw the tapered portion of said pin bodyand base member tightly together.

4. The process of manufacturing an insulator support comprising thesteps of forming a pin body having portions of different diametersconnected by an intermediatetapered portion, separately forming a basemember to support said pin body and having a socket to fit saidintermediate tapered portion, and forming the socket in said base memberin separate steps including a combined punching and shaping operation.

In testimony whereof I have signed In name to this specification on this24th day of February, A. D. 1923.

" ARTHUR O. AUSTIN.

